JeremyM
Lifetime Supporting Member
Hi all,
I'm generating AOIs for lots of our shipped components and, for the purpose of eliminating superfluous functionality/bloat, I got stuck thinking about the HOA concept as applied to individual components in a system. Example: an AOI driving an Ethernet VFD.
Whether or not the overall system has an HOA mode selection as example:
- Off = nothing attached will run from system hardware- or software-based (Ethernet) outputs.
- Hand = anything individually can run manually, if in its own 'manual' mode. No consideration of remainder of system.
- Auto = process/permissive-based run, no other external triggers permitted (short of mode change).
Does the component itself having an Off mode ever make sense?
- It's not exactly an actual means of lockout; would that just leave Manual/Auto/(maybe Commission) modes and hardwired safety-off?
- On system power-up, is the most-recently used mode the desired one? Or should the initial state be Manual?
- If a component is placed into Off while the system is in Auto, does the entire thing halt? Is there a situation demanding a stop like this that a safety circuit couldn't handle? Is a liability actually introduced with the addition of an Off mode?
Or am I missing another angle?
Thanks!
I'm generating AOIs for lots of our shipped components and, for the purpose of eliminating superfluous functionality/bloat, I got stuck thinking about the HOA concept as applied to individual components in a system. Example: an AOI driving an Ethernet VFD.
Whether or not the overall system has an HOA mode selection as example:
- Off = nothing attached will run from system hardware- or software-based (Ethernet) outputs.
- Hand = anything individually can run manually, if in its own 'manual' mode. No consideration of remainder of system.
- Auto = process/permissive-based run, no other external triggers permitted (short of mode change).
Does the component itself having an Off mode ever make sense?
- It's not exactly an actual means of lockout; would that just leave Manual/Auto/(maybe Commission) modes and hardwired safety-off?
- On system power-up, is the most-recently used mode the desired one? Or should the initial state be Manual?
- If a component is placed into Off while the system is in Auto, does the entire thing halt? Is there a situation demanding a stop like this that a safety circuit couldn't handle? Is a liability actually introduced with the addition of an Off mode?
Or am I missing another angle?
Thanks!
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